Derek H. R. Barton

Oxoammonium salts as oxidizing agents: 2,2,6,6-tetramethyl-1-oxopiperidinium chloride

Abstract A study of the scope of the oxidizing ability of the oxoammonium chloride (1) revealed that phenols, enolizable ketones, phosphines, amines and anilines were reactive but that olefins, aromatic ethers, sulfides, and sulfones did not react.

Catalytic oxidation of thiocarbonyl compounds involving the use of 1,2-Dibrometatrachloroethane as a brominating reagent for diaryl teII species

1,2-Dibromotetrachloroethane acts as a useful brominating reagent for diaryl TeII species in the establishment of a room temperature catalytic cycle for the conversion of thiocarbonyl compounds to their oxo analogues.

Synthetic methods for the preparation of D- and L-pseudo-sugars from D-glucose

Starting from D-glucose and using the Ferrier rearrangement to obtain the cyclohexanone (1), a convenient synthesis of crystalline pseudo-α-D-glucopyranose (15), its congeners (16) and (17), as well as their partially protected derivatives has been carried out.

Expedient synthesis of natural (S)-sinefungin and of its C-6′ epimer

Sinefungin 1a and 6-epi-sinefungin 1b have been prepared from adenosine and L-aspartic acid. The key step in the synthesis was the coupling of the radical derived from 14 with the unsaturated amide 13. The latter was obtained by a radical reaction from L-aspartic acid and olefin 11. Thus the carbon skeleton is constructed in two radical coupling reactions.

TOTAL SYNTHESIS OF THE THYMIDINE ANALOGUE OF SINEFUNGIN

Abstract The carbon skeleton of “Sinethymidin” 4 was constructed by two radical coupling reaction. The first step was a coupling of the radical derived from 2 and the unsaturated amide 5. The olefin 6 thus obtained was added to the radical derived from the known N-hydroxy-2-thiopyridinone aspartic ester. “Sinethymidin”, tested for its antileismanial effect, was devoid of activity.

Synthesis of branched-chain D-myo-inositols using the [3,3]sigmatropic Claisen rearrangement

A new and efficient synthesis of branched-chain cyclitols and their congeners utilizing a stereospecific Claisen rearrangement is reported.

Complementary use reversed-phase, normal-phase and chiral high-performance liquid chromatography for the study of the stereoisomers produced in decarboxylative alkylation of tartaric acid

Multi-dimensional high-performance liquid chromatographic analyses were conducted to study the various products formed in the course of the radical decarboxylative alkylation of the methylisopropylidene half-ester of (R,R-(+)-tartaric acid. The results obtained after sequential conversion show the presence of approximately 4% of (R,S)-dimethylisopropylidene tartrate and 96% of (R,R)-(+)-dimethylisopropylidene tartrate. Thus the stereoselectivity of the reaction under study is sufficiently high (ca. 25:1) for synthetic purposes.